Former Vice President Al Gore has some concerns about the man President Trump chose to head the Environmental Protection Agency, and he didn’t hesitate on Monday to say what he really thinks.

Gore spoke with Judy Woodruff on PBS NewsHour where she asked him about Scott Pruitt and his skepticism about the scientific consensus on climate change. Gore said that Pruitt’s ideas exemplify the debate over facts the Trump administration has caused, and that eventually, “a false belief collides with physical reality.”

“We have to address this,” Gore said. “But putting someone in the EPA who denies even the most basic scientific truth about this, you know, the old cliches are you can say the Earth is flat, but it doesn’t mean you’re going to fall off the edge.”